As used herein, a network element (e.g., a router, switch, bridge) is a piece of networking equipment, including hardware and software, that communicatively interconnects other equipment on the network (e.g., other network elements, end stations). Some network elements are “multiple services network elements” that provide support for multiple networking functions (e.g., routing, bridging, switching, Layer 2 aggregation, session border control, Quality of Service, and/or subscriber management), and/or provide support for multiple application services (e.g., data, voice, and video). Subscriber end stations (e.g., workstations, laptops, netbooks, palm tops, mobile phones, smartphones, multimedia phones, Voice Over Internet Protocol (VOIP) phones, user equipment, terminals, portable media players, GPS units, gaming systems, set-top boxes) access content/services provided over the Internet and/or content/services provided on virtual private networks (VPNs) overlaid on (e.g., tunneled through) the Internet. The content and/or services are typically provided by one or more end stations (e.g., server end stations) belonging to a service or content provider or end stations participating in a peer to peer service, and may include, for example, public webpages (e.g., free content, store fronts, search services), private webpages (e.g., username/password accessed webpages providing email services), and/or corporate networks over VPNs. Typically, subscriber end stations are coupled (e.g., through customer premise equipment coupled to an access network (wired or wirelessly)) to edge network elements, which are coupled (e.g., through one or more core network elements) to other edge network elements, which are coupled to other end stations (e.g., server end stations).
In a hierarchical network, the backhaul portion of the network includes the intermediate links between the core, or backbone, of the network and the small subnetworks at the edge. For example, while computers communicating within a single local area network (LAN) in an enterprise constitute a local subnetwork, the connection between the LAN and the rest of the world begins with a backhaul link to the core of the service provider's network. Some specific examples of network elements in such a network include edge routers (ER), for example SmartEdge Router from Ericsson, Inc., that connect the backbone portion of the network to the backhaul portion of the network. Network elements that make up the backhaul portion include packet optical transport platform devices (POTP) that combine layer-2 (L2) Ethernet aggregation functionality with legacy synchronous optical network (SONET) or synchronous digital hierarchy (SDH) support. One example of a POTP is an Optical MultiService transport element (OMS) from Ericsson, Inc. that provides Ethernet internetworking with core networks based on SDH. OMS can provide connectivity to an enterprise customer directly. OMS can also be connected to mobile backhaul gateway devices such as mini-links to interface with radio base stations or to digital subscriber line access multiplexer devices (DSLAMs) to provide connectivity to residential customers.
These network elements may be distributed all over the world, and utilizing the existing networks to provide low-cost virtual private networks (VPN) for enterprises has gradually become a major concern of carriers. Designing and provisioning these distributed networks can be a complex and labor-intensive task involving configurations of numerous different network elements across network paths. Adding to the complexity of managing such networks, a wide variety of service types are deployed within a network. Some of these service types include Layer 2 Multiprotocol Label Switching (MPLS) Virtual Leased Lines (VLLs) and Virtual Private LAN Service (VPLS), Layer 3 MPLS Border Gateway Protocol (BGP) VPNs, site-to-site IP Security (IPSec) VPNs, and legacy Layer 2 circuit-based Virtual LANs (VLANs). Another service type is MPLS-Transport Profile (TP), which is an extension of MPLS that includes characteristics and enhancements to meet packet transport requirements. Each service type may carry a mix of subscriber services such as video-on-demand or pre-paid wireless access with each of these subscriber services having a different level of Quality of Service (QoS) requirement. By providing a centralized tool to design and provision these various services, a network service manager simplifies a service designer's tasks of creating and managing complex services in a network. A network service manager is a service provisioning application that is implemented in and part of a network service manager server system. The network service manager server is interconnected to and manages network elements in a network. The network service manager server communicates with the network elements in a network to configure and provision the network elements and provides network monitoring, troubleshooting and reporting capabilities.
Protocols such as Resource Reservation Protocol (RSVP) allows for sequential reservation of resources in network elements across network paths to perform decentralized network bandwidth reservation. RSVP works by establishing a RSVP session through the exchange of reservation signaling in protocol messages along the network path. Each RSVP-supported network element along the network path that the protocol messages pass through reserves the resources as specified in the protocol messages. More recent developments such as the traffic engineering extension of RSVP (RSVP-TE)) seeks to improve on RSVP by allowing the flexibility to adjust nodes and change network paths in an established session and still maintain the same level of QoS.